Illinois income tax calculator

Taxable income is not salary

The number the brackets apply to is what is left after deductions. For most people that is the standard deduction and nothing else: $16,100 for a single filer in 2026, $32,200 filing jointly, $24,150 for head of household.

Someone earning $60,000 has $43,900 of taxable income, and the top rate they touch is 12%, not 22%. That single distinction accounts for most of the confusion about how much tax a salary attracts. Almost every rate of thumb people carry around is applied to the wrong number.

The tool asks for annual income before deductions and takes the standard deduction off for you, because that is what the overwhelming majority of filers claim. If you itemise, subtract the difference yourself before entering the figure.

Several other things come off before the standard deduction is even reached, and the tool does not model any of them. Traditional 401(k) and traditional IRA contributions, health savings account contributions, student loan interest within the published cap, and half of any self-employment tax are all adjustments to income rather than itemised deductions, which means a filer receives them whether or not they itemise. Someone earning $75,000 who defers $10,000 into a workplace plan is running this calculation on $65,000 rather than $75,000, and the difference is worth about $2,200 of federal tax at that income.

The worked example, at the default inputs

The calculator opens on $75,000 of annual income, filing single, with no state selected.

Taxable income is $75,000 minus $16,100, which is $58,900. Three bands are in play.

The marginal rate is 22%, because the last dollar sits in the third band. The effective rate is $7,670 divided by $75,000, which is 10.2%. The gap between those two numbers is the whole point of a progressive system, and it is why quoting a bracket as though it were a tax rate is misleading.

Change the filing status to married filing jointly on the same $75,000 and the standard deduction rises to $32,200, leaving $42,800 taxable. The 10% band runs to $24,800 for joint filers and the 12% band to $100,800, so the bill is $2,480 plus $2,160, which is $4,640. The marginal rate drops to 12% and the effective rate to 6.2%. The income did not change. The schedule did.

Add a state. Colorado is flat at 4.4% with a standard deduction we hold at $16,100, so its bill on $75,000 is $2,591.60 and the combined effective rate reaches about 13.7%. Pick Texas or Tennessee and the state line is zero. Pick New York and the tool says nothing, which the next section explains.

What is the difference between marginal and effective rate?

Marginal is the rate charged on your next dollar. Effective is what you actually paid across every dollar.

They are almost never close. In the worked example above they are 22% and 10.2%, a gap of nearly twelve points. The marginal rate is the right number for a decision about extra income: a bonus, overtime, a side contract, a deductible retirement contribution. The effective rate is the right number for a budget, because it describes the year you actually had.

Two consequences follow, and both are practical. First, a deduction is worth your marginal rate, not your effective one, so $1,000 into a traditional 401(k) saves a 22% filer $220 rather than $102. Second, a credit is worth its face value regardless of either rate, which is why a $1,000 credit beats a $1,000 deduction for everyone.

Why does the tool refuse to estimate some state bills?

Because we hold a top marginal rate for graduated states and not the bracket table, and a top rate applied to every dollar is not an approximation. It is a much larger number.

Nine states do not tax wage income at all. Roughly a dozen apply one flat rate to everything above an allowance, and those the tool computes exactly, because two published figures are all the arithmetic needs. The rest run their own graduated schedules, which do not resemble the federal ones and often start at much lower incomes.

For those states, applying the top rate would be indefensible. California's top rate of 13.3% starts above a million dollars of income. Using it on $75,000 would produce a bill roughly four times the real one. So the tool returns nothing, prints the state's top rate for reference, and says plainly that it is not estimating. That refusal is deliberate and it is the same policy every calculator here follows: see our methodology. The state pages carry the published figures we do hold for each state.

The flat states are where the tool is at its most useful, because two published numbers describe the whole system. Colorado charges 4.4% after an allowance we hold at $16,100. Illinois charges 4.95% and we hold no standard deduction figure for it, so the rate applies to the whole amount. Arizona charges 2.5% after $8,350, North Carolina 3.99% after $12,750, and Pennsylvania 3.07% with no allowance in our data set. Those five alone span a fourfold difference in state liability on an identical salary, a wider spread than most people assume exists between states that all describe themselves as low tax.

What does another $10,000 of income cost?

At the default $75,000, the next $10,000 lands entirely inside the 22% band, which runs from $50,400 to $105,700 of taxable income. Federal tax rises from $7,670 to $9,870, so the extra income costs $2,200 and delivers $7,800 before FICA and any state tax.

That is the number to use for any decision at the margin: a bonus, a side contract, a year of overtime, a judgement about whether extra work is worth taking. The rate stays at 22% until taxable income passes $105,700, at which point it becomes 24%. Run the logic backwards and it prices a deduction just as well. Ten thousand dollars into a traditional retirement account saves $2,200 of federal tax at this income and nothing at all against FICA, which is why the investing section treats the marginal rate as the first input to any contribution decision.

Filing status changes the answer completely. On $75,000 of joint income the next $10,000 is taxed at 12%, because the joint 12% band runs to $100,800 of taxable income. The same extra work is worth $1,000 more after federal tax to a married couple than to a single filer, entirely because of where the bands sit.

The mistakes people make with brackets

Thinking a raise into a new bracket taxes everything at the higher rate. Only the dollars above the threshold move. This belief costs real money when it makes someone turn down a raise or refuse overtime.

Applying the bracket rate to gross salary. The brackets apply to taxable income, which is salary minus deductions. Skipping that step overstates the bill by roughly a fifth for a typical earner.

Itemising out of habit. Itemised deductions only help if they exceed $16,100 single or $32,200 jointly. That usually needs a substantial mortgage or unusually large charitable giving.

Confusing withholding with liability. What your employer takes is a prepayment calibrated by your W-4. What this tool shows is the liability. The two settle against each other in April.

Ignoring credits entirely. Deductions reduce taxable income; credits reduce tax owed. For households with children or education costs, credits often matter more than any bracket question.

Before you file

• Confirm your filing status, since it changes both the deduction and the bands
• Total your itemised deductions and compare them against the standard amount
• Collect every W-2 and 1099, including small ones you may have forgotten
• Check whether you qualify for the child tax credit or the earned income credit
• Add any retirement contributions made before the filing deadline
• Compare year-to-date withholding against the liability this tool estimates
• Run the IRS Tax Withholding Estimator if the two are far apart

If withholding is short by a large margin, an estimated payment before the deadline reduces the underpayment penalty. Our tax guides go through the safe harbour rules.

What this calculator does not cover

• Credits, which come off the tax rather than the income and can be worth far more than a deduction of the same size. The child tax credit, the earned income credit and education credits all work this way.
• Capital gains and qualified dividends, taxed on their own schedule with 0%, 15% and 20% thresholds rather than the ordinary bands.
• The alternative minimum tax, which runs a parallel calculation with its own exemption.
• The additional Medicare surcharge of 0.9% on wages above $200,000 single or $250,000 jointly, and the net investment income tax that shadows it.
• Self-employment tax, which is a separate 15.3% payroll charge on business profit and is handled by its own tool in our calculators.
• Above-the-line adjustments, such as student loan interest, HSA contributions and half of self-employment tax.

If your return contains any of those, this gets you an order of magnitude rather than a filing figure. It is a good tool for answering "what does another $10,000 cost me" and a poor one for answering "what do I owe". This page is general information, not tax advice: see the disclaimer.